Sorry, I thought you were just asking is it possible to see the context. I wasn't looking to defend the product. That said, though...
I don't think Circles intends to aid in setting social context for other people. It's intended to help the sharer set context for who will see their content. Google is betting that people will share more information if they can limit it to the right groups of people.
As a commenter on this content, I don't get to reset the context or modify it. I can either trust the initial poster's choice or I can dig in further. The mental model is pretty simple: I trust the poster or I take a look around the room and see who else is there. I think when people do dig in further, they will either see a small group of people that they recognize or a large group of people which will set them in "public" context mode for commenting.
I don't think Circles intends to aid in setting social context for other people. It's intended to help the sharer set context for who will see their content. Google is betting that people will share more information if they can limit it to the right groups of people.
As a commenter on this content, I don't get to reset the context or modify it. I can either trust the initial poster's choice or I can dig in further. The mental model is pretty simple: I trust the poster or I take a look around the room and see who else is there. I think when people do dig in further, they will either see a small group of people that they recognize or a large group of people which will set them in "public" context mode for commenting.